Electrical equipment aboard aircraft when subjected to harsh operational conditions frequently fail or break down. Such electrical equipment may have electronic equipment containing circuit cards and are commonly referred to as “weapon replaceable assemblies,” or WRAs. Typically, there are many WRAs within an aircraft and each is designed to be removed and replaced easily. However, narrowing a fault to a single WRA can be a time-consuming, labor-intensive, and often a very frustrating and costly process.
Frequently, in order to isolate a fault to a single WRA, a built-in-test (BIT) is performed which serves well its intended purpose. However, some aircraft have no BIT at all or even on aircraft with sophisticated BIT systems, locating the sources of intermittent faults (those faults not repeating regularly), as well as, false alarms can be a very difficult process.
The WRAs are connected by large bundles of wires, some bundles containing hundreds of wires. Currently, there is no known way to examine the electrical signals on these bundles while the WRAs are still in operation. It is desired to provide a system that allows for isolating faults between WRAs, while the WRAs are operational. Further, it is desired to provide a system that could be used to break diagnostic ambiguities between WRAs within an aircraft.